Is anybody aware of any extension that could enable RT to send some kind of warning, to the user like a pop up window, a sound notice, a voice or whatever, that could awake the user attention when a new mail arrives to RT, with indication of the mail it refers to?

That would be very useful for my NOC with many tickets opened at the same time and many customers sending replies to RT at any time.

I think that it would be linked to the new transaction of type "Correspond" created when a mail is fetched and acknowledged and added to the ticket.